The present invention relates to coupling a membrane to the skin of a human being, for instance as a patient undergoing therapeutic or diagnostic treatment.
For purposes of medical diagnostic and/or therapeutic treatment, it has become more and more customary to use certain equipment by means of which radiation or waves such as shock waves or ultrasonic vibrations are coupled into the body of the patient without invasive surgery and without incurring any radiation energy losses or at least under and without conditions in which any losses are minimized.
As a first preparatory step for attaching a membrane to the skin, the body hair in the area in question is usually shaved off, and a gel layer is placed upon that bare skin. Now, the membrane of the medical treatment device or apparatus is forced against that gel layer. The purpose of this procedure is to provide an airfree and gapless coupling of the membrane to the skin, i.e. without inclusion or interposing of air bubbles. The membrane is in engagement and interfaces with the gel layer; the gel layer on the other hand is placed onto the skin directly and there should be no air bubbles anywhere. This being the desired state, it was found however that in practice bubbles are included, in the gel layer for example, through carelessness on part of the technician or nurse. These bubbles may be small but still their presence is highly detrimental and may in fact render questionable the success of the treatment i.e. the effect of the treatment may be diminished or even become ineffective entirely. Of course, medical technicians or physicians can acquire adequate manual skill and proficiency in the application of the gel layer such that indeed air bubbles are not included. This skill however is highly personal and simply cannot be expected as a matter of course.
It has, therefore, been suggested to evacuate the space between the skin of the patient on one hand and the membrane on the other hand, and to provide an immediate and direct contact between membrane and skin without, hopefully, intrusion of air bubbles. It was found in practice, however, that this bubblefree connection be guaranteed and is not even improveable through skillful handling. For these reasons therefor, one had to proceed in certain instances in a rather cumbersome fashion. For example, lithotripsy by means of shock waves such as the comminution of kidney stones has been practiced by placing the patient into a tub that is filled with water; the water is the coupling medium between the skin and the shock wave generator and focusing device, whereby however, the water had to be carefully degassed. This procedure solves the problems of coupling the shock waves into the body of the patient, but it is obvious that placing the patient into a tub just for that purpose is a rather cumbersome way of proceeding. Still, this has been practiced in the past quite successfully but on the other hand it is apparent that there is room for improvement.